Reservoir desk stand



May 22, 1951 LP. MARTIN RESERVOIR DESK STAND 2 Sheets-Sheet 1 Filed Jan. 16, 1947 May 22, 1951 E P. MARTIN 2,553,598

RESERVOIR DESK STAND Filed Jan. 16, 1947 2 Sheets-Sheet 2 IIII'IIIIII mill 4 2 22 MW TI )6 l ll L m 1 Wi l n u I 62 2/ 27 /7 Patented May 22, 1951 RESERVOIR DESK STAND Lynn P. Martin, Fort Madison, Iowa, assignor to W. A. Sheaifer Pen Company, Fort Madison, Iowa, a corporation of Delaware Application January 16, 1947, Serial No. 722,451

7 Claims.

This invention relates to desk stands for supporting and supplying ink to dip-type writing pens: more particularly the invention relates to reservoir desk stands wherein the ink is supplied from a reservoir in controlled quantities to a well into which a pen may be dipped; and the invention has for an object the provision of improved and compact desk stands of this character which present an attractive appearance and are reliable in operation.

Desk stands of the reservoir type having a pen supporting opening disposed over a well for receiving the point of a pen have heretofore been constructed in such a manner that the ink is automatically supplied to the well from an inverted ink bottle or similar reservoir as the ink in the well is used up by the writing pen. Such prior desk stands, however, have been characterized by a tendency of the ink in the well to dry y up due to excessive evaporation, and have been found objectionable due to the fact that tipping, improper positioning or jarring of the desk stand has resulted in spilling of the ink from the stand. Furthermore, such prior constructions have been rather cumbersome and unsightly in appearance, and difiiculties have been encountered in replenishing the supply of ink either by inverting a standard ink bottle in the desk stand or otherwise refilling the reservoir without spilling of the ink. Accordingly, it is afurther obiect of this invention to provide a reservoir desk stand wherein an excessive flow of ink from the reservoir to the well is prevented at all times even through th stand is tilted or inverted from its normal position.

An additional object of the invention resides in the provision or" a reservoir desk stand wherein the reservoir may be quickly and easily filled or refilled without danger of spilling the ink.

It is a still further object of the invention to provide a desk stand having an expansion chamher for receiving excess ink which may overflow from the well, as for example when excess ink is expelled from the reservoir by an increase in the ambient temperature conditions and wherein spillage of the excess ink from the expansion chamber is prevented even. though the stand is tipped or jarred.

In carrying out the invention in. one form a reservoir desk stand is provided having a well and a reservoir disposed in laterally spaced relation together with means forming afeed passageway extending laterally from the. reservoir to the well, the reservoir being sealed against the entry of air therein-to except through: the feed passageway. More particularly, means are provided for cooperating with the feed passageway to control the admission of air to the reservoirand the consequent flow of ink to the well,. the control means and. the feed passageway being effective when the desk standis tipped from its: normal position to provide a liquid seal which functions to prevent the flow of excess ink from the reservoir during tipping of the stand. An expansion chamber surrounding the well serves to contain any excess ink which may overflow from the well and is provided with an opening in the top wall thereof through which a pen may be inserted into the well, the opening being surrounded by a downwardly extending wall or guard for preventing spillage of the excess ink from the expansion chamber even though the stand is tipped, and capillary means associated with the expansion chamber and the well are provided for returning to the well the excess ink contained in the expansion chamber.

Fora more complete understanding of the invention reference should now be had to the drawings, in which Fig. 1 is a perspective view of a reservoir desk stand embodying the present invention;

Fig. 2 is an end elevational view of the d-sk 'tand shown in Fig. I;

Fig. 3 is an exploded per pective view shot-ring the upp-r and lower body portion from wh ch the d:sk stand is formed, the upper body portion being upturned on one edge more clearly to illustrat theinternal construction Fig. 4 is an exploded perspective VlGW' of the lower body portion shown in Fig. 3 in disassembled relation with a closure strip, the lower body portion being inverted to illustrate the constructional details;

Fig. 5- is a plan view of the lower body portion partially in section along the line 5-5 of Fig. 3:

Fig. 6 is a longitudinal sectional view taken along the line 66' of Fig. 2;

Fig. '7 is a similar longitudinal sectional View takenalong the line 1-4 of Fig. 2';

Fig. 8 is a transverse sectional view taken along the line 8--8 of Fig. 1;

Fig. 9 is a similar transverse sectional view takenalong the line 9-9 of Fig. 6;

Fig. 10' is a detail elevational view of an insert member which may be employed in the filling passageway of the desk stand shown in Figs. 1-9, inclusive, if desired;

Fig. 11 is an end view of the insert member shown in Fig. 10; and

Fig.- 12 is a sectional view taken along the line i2!2 of Fig. 11.

Referring now to the drawing, the invention is shown as embodied in: a reservior desk stand l5 which is of substantially rectangular configuration having end walls It and I1 and side walls [8 and 19. Preferably, the desk stand I5 is formedof two body portions: 20 and 2| (Fig. 3) the upper body portion including the end and sidewalls I6 andv l1 and [8 and I9 and also including a top wall 22. The lower body portion 2 l: provides the bottom wall 23 for the desk stand and, as shown, the end and side walls formed on the upper body portion are recessed at their lower edges so as to permit the upper body portion 23 to telescope over the lower body portion, the edges of the bottom wall 23 being arranged to abut the shoulder 24 which extends around the end and side walls of the upper body portion.

Extending transversely of the stand or base [5, and preferably forming an integral part of the upper body portion 20, is the wall '25 which serves to divide the space within the stand into a reservoir 26 and an expansion chamber 21. In order to provide a tight seal when the upper and lower body portions are assembled, the bottom wall 23 on the lower body portion 2| is preferably provided with a transversely extending along the side wall l8 of the base and a laterally extending portion 32 which extends along the end ll of the base. As shown best in Fig. 3 the portions 3| and 32 of the feed passageway are preferably formed integrally with the lower body portion 2| and with the well 30. The passage- :ways 3! and 32, as shown best in Fig. 4, extend through the bottom wall 23 and a small auxiliary passageway 33 is provided communicating with the portion 32 of the feed passageway intermediate its ends and extending parallel to the passageway portion 32 beneath the bottom wall of the base. Communicating with the auxiliary passageway 33 at the end thereof and extending angularly upwardly therefrom so as to communicate with the bottom of the well3|l is a small passageway 34 which likewise forms a portion of the feed passageway and serves to supply ink to the bottom of the well from the reservoir 26.

Referring now to Fig. 3, the end of the longitudinal passageway 3| is adapted to communicate with the reservoir 26 and, as shown in Fig. 3, the wall which divides the base into the reservoir 26 and the expansion chamber 21 is provided with an opening 35 communicating with the end of the passageway portion 3|, one surface of the wall 25 being recessed, as indicated by the reference numeral 36, to receive the end of the passageway portion 3| and provide a tight seal between the reservoir and the feed passageway.

As shown best in Figs. 6 and 9, the transverse passageway portion 32 of the feed passageway extends beyond its point of communication with the auxiliary passageway 33 and terminates directly behind the well 30, the upper wall of the feed passageway portion 32' being provided with a downwardly extending dam 31 disposed in spaced relation to the end wall of the passageway 32 to define a regulating chamber 38. Extending laterally from the regulating chamber .38 and communicating with the well 30 at a point above the normal liquid level therein is an air passageway 39, the purpose of which will be more fully set forth hereinafter.

" As shown best in Figs. 1, 3 and 6 the portion 4 i the expansion chamber 21 is provided with an opening 43 which is offset from the well 30, and a downwardly extending guard or wall 4|, which surrounds the opening 43, is angularly disposed as shown so that a pen inserted through the opening 30 is supported in an inclined position by the wall 4| with its point disposed in the well 33. Preferably, the guard or wall 4| is provided with grooves 42 so as to present a discontinuous supporting surface and prevent an accumulation of ink on the writing end portion of the holder.

In order to provide for filling of the reservoir 26 without danger of ink being spilled out of the base or stand during the fillin operation, the upper body portion 28 of the stand is provided, as shown best in Fig. 3, with a filling passageway 43 which communicates with a suitable aperture 53 in the wall 25 and extends across the expansion chamber 2'! so as to communicate with the exterior of the base through the end wall As shown best in Fig. 7, this filling passagaway 43 is internally threaded as indicated by the reference numeral to receive a suitable closure member G6 which is provided with coperating threads, the outer end of the closure member 46 being provided with a suitable transverse groove 47 and a rib 48 to facilitate proper tightening of the closure member or removal of the closure member from the filling passageway.

It will be understood that when the upper and lower body portions 20 and 2| are assembled to form the base or stand l5 all of the cooperating joints and edges will be suitably sealed to insure that the reservoir is rendered air tight, and in order to prevent assembly of the upper and lower body portions in improper end-to-end relation the lower body portion 2| is provided along one edge with a notch 49 adapted to receive a corresponding projection 50 in the upper body portion 23, the notch 49 and projection 58 being oiiset longitudinally from a mid-position so as to prevent assembly of the two body portions except when in proper end-to-end relation. The lower wall of the passageway portions 3|, 32 and 33 and of the regulating chamber 38 comprises a properly shaped closure strip 5| (Fig. 4) which is adapted to fit within a suitable recess formed in the underside of the lower body portion 2| and to be sealed therein by any suitable means.

Having in mind the above described features of construction of the reservoir desk stand IE, it is thought that a complete understanding of the invention may be had from a description of the operation. In order to fill the reservoir 26 of the desk stand IS with ink, it is necessary only to turn the base or stand to an endwise position in which it rests on the end wall l6 and then withdraw from the filling passageway 43 the closure member 46, whereupon ink may be poured through the filling passageway into the reservoir. It will be noted that during the filling operation the well 38 is at the upper end of the base adjacent the end Wall and consequently there is no danger of ink leaking or spilling out of the well. Furthermore, air from the reservoir may pass freely through the feed passageway portions 3| and 32 and out of the well 38 into the expansion chamber 21 as this air is displaced from the reservoir 25 by the ink.

Although the ink may be supplied to the reservoir from any suitable container or bottle, the chances of accidental spilling of the ink will be minimized through the use of special containers which are available on the market. These special co tainers. or bottlcs a e prov ded: wi h; a; neck f. sufificie tly sma l. di meter to fit i hin. t e enlarged outer end of the filling passageway 43: o that the bottle may be. Completely inverted with its neck inserted into the filling passageway. One type of small necked bottle available on the market is provided, in addition to. the usual outer seal or cap, with an inner seal which must be displaced or punctured before ink can be poured from the bottle. Where such a container is. used to supply ink to the reservoir 26 the filling passageway 43 of the desk stand is preferably pro vided with an insert member such as is shown best in Figs. 7-12, inclusive. This insert. member 52 comprises a tubular body adapted to fit within the filling passageway 43 as shown in Fig. 7. The inner end of the insert member 52 is provided with a plurality of grooves 53 on its outer periph ery through which the ink may freely flow around the outside of the insert member when the member is positioned in the filling passageway. Likewise, the insert member 52 is provided with a flange 54 adapted to rest on a suitable shoulder 55 formed intermediate the ends of the filling passageway, and a suitable finger or arm 56 extends outwardly from one end of the insert member 52 to a position closely adjacent the end of the filling passage.

When the container having the above referred to inner seal is inverted over the open upper end of the filling passageway and pressed downwardly thereinto the arm 56 functions to displace the inner seal only after the neck of the bottle has entered the filling passageway so that the ink may thereafter flow into the passageway through the reservoir. Thus there is no danger of spilling the ink before the bottle is properly positioned relative to the filling passageway. As shown best in Fig. '7 the closure member 43 is preferably of hollow construction so as to receive the outer end of the insert member 52 when the closure member is placed in position to seal the filling passageway 43. Thus the insert member may remain permanently in the filling passageway 43 and will be available for effecting automatic. opening of the specially sealed ink bottle whenever the closure member 46 is, removed.

After the reservoir has been filled and the closure member 46 screwed tightly into. place. so as to seal the filling passageway 43., thereby preventing the entry of air into. the reservoir through the filling passageway, the desk stand I5. may be placed in its normal position for supporting and supplying ink to a. pen. When the stand is first returned to its normal position ink flows from the rreservoir through the portions 3!, 32, 3.3. and 34 of the feed passageway to the bottom. of the well 30 and the level of the ink in the well in the feed passageway will rise until the ink completely fills the opening 51 beneath the dam 31., which open-. ing 51 communicates the regulating chamber 38 with the portion 32 of the feed passageway. As soon as the ink in the feed passageway reaches a sufficient height to close off the opening 51 a liquid seal is provided for the reservoir and the flow of ink therefrom will cease because no. more air can be admitted to the reservoir through the feed passageway. During the rise of. ink in the feed passageway and the well air is of course expelled from the feed passageway through the opening 39 communicating the regulating chamber 38 with the upper portion of the well 30. The wall or dam 3.7 is. so. proportioned as to insure that. when the flow of ink from the reservoir stops by reason. of. the creati n of. the liquid seal the level or the ink n the well 30: will be at the e.

siredv height to. furnish ta a pen insert d hrou h, t e. openin 49 so. that its writing p in rests in the well.

As ink; is withdrawn from the well 30 by the pen the level of the. ink; in the well tends to fall, since no more; ink: can flow out of the reservoir which is; sealed; from the atmosphere. However, the body of contained in the regulating chamber 38; is open to the atmosphere through the passage. 39 a consequ ntly ink. will be drawn from the regulating chamber through the sassageways- 33. and 34,. thereby reducing the level of the ink contained in the; regulating chain! en h n he. level: of; the ink co ained in. the regulating chamber 38 falls to approximately the bottom edge of the dam 31;, the liquid seal will be broken and a, bubble f air will pass under the dam into the feed passageway portion 32,, and since this air may pass through the feed passageway into the reservoir a corresponding amount of ink will flow out of the reservoir into the regulating chamber 38 and the well 30 so as to reestablish the desired ink level in the well.

The above described action, i. e., the admission of a bubble of air into the reservoir whenever the ink level in the well and the regulating chamber decreases. a predetermined amount and the consequent flow of ink to the regulating chamber and well, will continue until all of the ink from the reservoir has been supplied to the well for use therein. The provision of an air inlet which is independent of the pasageway 34 through which ink; is supplied to, the bottom of the. well 30 enables the desk: stand to maintain automatically an exceptionally close control of the ink level in the well.

As will be apparent, there is a body of air contained in the reservoir 26- above, the body of ink therein, and in the event; of an increase in the ambient temperature to which the desk stand is subjected this confined body of airexpands' so as to force excess ink out of the reservoir into the well 30. Such excess ink is discharged from the well 30 through a fissure or cut 60 of capillary dimensions or may even. overflow the lower edge of the well 30 into expansion chamber 27 where it will be retained. Under ordinary temperature changes, however, the excess ink forced from. the reservoir will pass through the fissure 60 without materially increasing the. level of the ink in the well 30, and accordingly the ink remains at a low enough level so that only the tip of the pen point is covered by the ink even though the expansion chamber 21 contains a considerable body of ink.

Whenever the ambient temperature decreases the confined bodyof air within the reservoir 26 of course contracts, and ink will be drawn from the expansion chamber 21: through the fissure cut 60, well 30 and the feed passageways 34, 33, 32 and 3| back; to the reservoir before any air will pass through the passageway 39 and the opening 57 into the feedpassageways. In order to accomplish this withdrawal of ink from the expansion chamber the proportions of the fissure cut 60 and the various passageways are so related that less force is required to draw the excess ink through the fissure so from the expansion chamber 2'! than is required to break the liquid seal beneath the dam 31. Consequently, repeated contraction and expansion of the body of air contained; within the reservoir 25 due to changes in the ambient temperature will not ex pel in o the expan on. chamber suificicnt ink to till the chamber above a level greater than that at which the desired ink level is maintained in the well 30. As heretofore indicated, one of the greatest difficulties encountered in prior reservoir desk stands has been the inability of the stand to control the ink level when tipped or jarred, and in such prior constructions all of the ink may run out of the reservoir in the event that the stand is tipped to an excessive angle. In desk stands embodying the present invention, however, the desired ink level in the well is maintained and the flow of excess ink from the reservoir is prevented when the stand is tipped to any angle or even if the stand is completely inverted. This desirable result is accomplished by the interrelation of the sealed reservoir, the various feed passageways and the well.

As is well understood in the art, air will not travel downwardly through a body of liquid nor will it travel any substantially lateral distance in a passageway filled with liquid, the body of liquid in either case serving as a liquid seal. Referring to Figs. and 6, if it is assumed that the stand is tipped up on end so as to rest on the end wall ll, it will be observed that the two passageways 34 and 39 extend downwardly from the respective ends thereof which are open to the atmosphere. Consequently, before any ink can flow out of these passageways into the expansion chamber 2! it would be necessary for air to travel downwardly through the ink in the passageways 3i and 39. Such travel of the air is impossible and, consequently, a liquid seal is provided which prevents the flow of ink from the reservoir 26 even though the'body of ink contained therein is at a much higher level than the well 3! Likewise, referrin again to Fig. 5,. let it be assumed that the stand is turned up on one side so as to rest on the side wall I8. Under these conditions admission of air to the reservoir 26 and the consequent overflow of ink from the reservoir through the well 30 would require that air pass downwardly through the portion 32 of the feed passageway. This again is an impossible condition and again a liquid seal is provided for the ink in the reservoir.

If the stand is tipped up so as to rest on the end wall IE, it will be apparent that the level of ink in the reservoir will fall below the open ing into the reservoir of the portion 3! of the feed passageway, and consequently no overflow of ink from the reservoir to the well is possible. Whenthe stand is tipped so as to rest on the side wall i9, the level of the ink in the reservoir will, under most conditions, fall below the opening into the reservoir of the portion 3! of the feed passageway, but even though the reservoir is completely full so that the level of the ink is above this opening there will be no un desirable flow of ink due to the fact that the passages 34 and 39 leading to the well are the same size and in the position of the stand are at the same level. Accordingly, the passage ways being substantially horizontal, there is no head of fluid sufficient to overbalance the air and fluid relationship so as to cause the ink to flow out and the air to pass into the feed passageways. 7

Thus it will be seen, that the only ink that may spill into the expansion chamber 2! when the stand is tipped, is the small quantity of ink contained in the well 38, which small quantity of ink will readily be contained within the expansion chamber 21 until such time as the stand is returned to its normal position, whereupon this excess ink in the expansion chamber 21 will I be returned to the well 30 through the fissure cut 60.

Even though a substantial quantity of ink should accumulate in the expansion chamber 21 due to extreme variations in ambient temperature conditions or to other causes, spillage of ink from the desk stand is prevented by the construction of the guard or wall 4| which surrounds the opening 48. It will be observed that this guard or wall, in any position to which the stand may be tipped, forms a barrier against the flow of ink out of the opening 40. Thus reservoir desk stands constructed in accordance with the present invention may be termed completely spill-proof regardless of the manner in which the desk stand is handled or positioned.

In order to insure that all of the ink from the reservoir 26 and any excess ink which may accumulate within the expansion chamber 21 will be available for use in the well 30, the lower body portion 2! of the desk stand is preferably so formed as to provide a slope to the bottom wall 23. As shown best in Fig. '7, this bottom wall slopes downwardly from the end wall l6 toward the intermediate wall 25 and downwardly from this intermediate wall to the end wall ll. Although the upper and lower body portions Zll and 25 may be made of any suitable material, they are preferably molded from a suitable moldable plastic material, and in order to provide greater mass or stability it may be de-, sirable to mount suitable metal pads or weights iil'on the lower surface of the bottom wall 23. For this purpose the undersurface of the bottom wall 23 is provided with integrally formed projections or rivets 62 adapted to extend through suitable openings in the metal plates or pads 63 (Fig. 4), the ends of the rivets 62 being thereafter formed to lock the pads or weights in the desired position.

.While I have shown a particular embodiment of my invention, it will be understood, of course, that I do not wish to be limited thereto since many modifications may be made, and I, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A reservoir desk stand comprising a reservoir, an expansion chamber adjacent said reservoir having an opening in the upper wall thereof, a well having a wall portion disposed in said expansion chamber for receiving the point of a pen through said opening, means forming a feed passageway extending laterally through said expansion chamber for connecting said well to said reservoir, said expansion chamber serving to contain excess ink overflowing from said well, and capillary means in said wall portion communicating between said expansion chamber and said well for returning said excess ink to said well.

2. A reservoir desk stand comprising a res ervoir, an expansion chamber adjacent said reservoir having a pen-receiving opening in the upper wall thereof, a pen-supporting wall surrounding said opening and extending angularly into said chamber from said upper wall, a well having a wall portion in said expansion chamber disposed in alignment with said opening and said angularly extending wall for receiving the point of a pen supported in said opening, means forming a feed passageway extending through said expansion chamber for connecting said Well to said reservoir, means in said passageway for controlling the flow of air therethrough from said expansion chamber to said reservoir to control the flow of ink to said well, said expansion chamber serving to contain excess ink overflowing from said well upon an increase in the ambient temperature, and capillary means in said wall portion communicating between said expansion chamber and said well for returning said excess ink to said well.

3. A reservoir desk stand comprising a reservoir, a well having a wall portion disposed in laterally spaced relation to said reservoir for receiving the point of a pen, means forming a feed passageway extending laterally from said reservoir to said well, an expansion chamber surroundin said well and having an opening in the top wall thereof permitting insertion of a pen into said well, regulating means for controlling the admission of air from said chamber to said passageway in accordance with the ink supply in said well, said passageway having portions extending angularly with respect to each other and cooperating with said regulating means to provide a liquid seal against the entry of air into said reservoir when said stand is tipped from a normal upright position thereby to prevent the flow of excess ink from said reservoir during tipping, said expansion chamber serving to contain excess ink overflowing from 1-:-

said well during tipping and excess ink flowing from said reservoir upon increasing ambient temperatures, and capillary means in said wall portion communicating between said expansion chamber and said well for returning excess ink from said expansion chamber to said well.

4. A reservoir desk stand comprising a hollow base, wall means extending across said base interiorly thereof to provide a reservoir and an expansion chamber disposed in side by side relation, a well having a wall portion in said expansion chamber adjacent the end of said base remote from said reservoir, means forming a feed passageway extending along one side and one end of said expansion chamber for supplyin ink to said well from said reservoir, said expansion chamber having an opening in the top wall thereof for permitting insertion of a pen into said well, means forming a filling passageway extending from said reservoir and across said expansion chamber and communicatin with the exterior of said base through the end wall thereof adjacent said well whereby said base may be disposed on the end thereof opposite said well during filling of said reservoir,

closure means for sealing said filling passageway to seal said reservoir against the entry of air thereinto except through said feed passageway, means cooperating with said feed passageway and effective upon sealing of said reservoir for controllin the flow of ink from said reservoir to said well, said expansion chamber serving to contain excess ink overflowing from said well, and a capillary passageway in said wall portion communicating between a bottom portion of said expansion chamber and said well for returning excess ink from said expansion chamber to said well.

5. A reservoir desk stand comprising a reservoir, an expansion chamber adjacent said reservoir having a bottom wall and an opening in an upper wall thereof, a well disposed in said expansion chamber for receiving the point of a pen through said opening, means independently of said expansion chamber formin a feed passageway for connecting said well to said reservoir, said expansion chamber serving to contain excess ink overflowing from said well, and a capillary passageway communicating with said reservoir and opening into said expansion chamber adjacent said bottom wall thereof permitting the flow of ink between said reservoir and said expansion chamber upon changes of pressure within said reservoir.

6. A reservoir desk stand comprising a hollow base, wall means extending across said base interiorly thereof to provide a reservoir and an expansion chamber in side by side relation, a well in said expansion chamber adjacent the end of said base remote from said reservoir, means formin a feed passageway extending along one side and one end of said expansion chamber for supplying fluid from said reservoir to said well, means forming a capillary passageway adjacent said base communicating with said reservoir and opening into said expansion chamber and permitting the flow of fluid between said reservoir and said expansion chamber upon changes of pressure within said reservoir, and an enclosed regulating chamber communicatin with said feed passageway having a downwardly extending dam member under which air passes from an upper portion of said regulating chamber into said feed passageway and reservoir as fluid is withdrawn from said well, said regulating chamber being provided with a vent in the form of a bore terminating in an inner side wall of said well above the opening of said feed passageway into said well.

7. A reservoir desk stand comprising a hollow base, wall means extending across said base interiorly thereof to provide a reservoir and an expansion chamber in side by side relation, a well having a fluid supply opening in the bottom thereof extending upwardly from said base in said expansion chamber adjacent an end of said base remote from said reservoir, means forming a fluid feed passageway extending along one side and one end of said expansion chamber for supplyin fluid from said reservoir to said fluid supply opening in said well, and an enclosed regulating chamber communicating with said passageway adjacent said well having a downwardly extending dam member under which air passes from an upper portion of said regulating chamber into said passageway and said reservoir as fluid is withdrawn from said well below a level determined by the lower edge of said dam, an upper portion of said enclosed regulating chamber above said lower edge of said dam being provided with a vent in the form of a bore opening into said well at a point spaced above said fluid supply opening, and a Wall of said well being provided with a capillary passageway communicating between the base of the expansion chamber and the well adjacent the fluid supply opening.

LYNN P. MARTIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,196,645 Bengue Aug. 29, 1916 2,249,616 Martin July 15, 1941 2,390,667 Sengbusch Dec. 11, 1945 

